The Family Leader, a prominent Iowa group that promotes Christian conservative social values, said Thursday it is asking all presidential candidates to sign a pledge regarding their personal convictions on traditional marriage.

The pledge is entitled, “The Marriage Vow – A Declaration of Dependence upon Marriage and Family.”

The organization’s chief executive officer is Bob Vander Plaats, a conservative evangelical leader who was the state chair of Mike Huckabee’s Republican presidential campaign when he won the 2008 Iowa Caucuses. Vander Plaats said the Family Leader will not support any candidate who declines to sign the pledge.

“If you are looking at being a leader of our great country….we would like to have you pledge personal fidelity to your own spouse and a respect for the marital bonds of others,” Vander Plaats told reporters at a news conference on the steps of the Iowa Statehouse.

U.S. Rep. Michele Bachmann, R-Minnesota, quickly signed the pledge Thursday, while an aide to to former Utah Gov. Jon Huntsman said he never signs any pledges. A spokesman for U.S. Rep. Ron Paul, R-Texas, said the congressman has reservations, while a representative of President Barack Obama’s Democratic campaign committee declined comment.

Former Minnesota Gov. Tim Pawlenty, a Republican, is reviewing the pledge, a spokesman said Thursday night. Several other GOP presidential candidates didn’t respond to requests for comment, including former Michigan Gov. Mitt Romney, former House Speaker Newt Gingrich, former Pennsylvania Sen. Rick Santorum, and retired Georgia businessman Herman Cain.

Presidential candidates who sign the pledge must agree to personal fidelity to his or her spouse, the appointment of “faithful constitutionalists” as judges, opposition to any redefinition of marriage, and prompt reform of uneconomic and anti-marriage aspects of welfare policy, tax policy and divorce law.

The Marriage Vow also outlines support for the legal advocacy for the federal Defense of Marriage Act, humane efforts to protect women and children, rejection of Sharia Islam, safeguards for all married and unmarried U.S. military service members, and commitment to downsizing government and the burden upon American families.

In addition, candidates are asked to recognize that “robust childrearing and reproduction is beneficial to U.S. demographic, economic, strategic and actuarial health and security.”

Alice Stewart, a Bachmann aide, said the congresswoman had no qualms about signing the Family Leader’s pledge. “She has been married for over 30 years and has a strong marriage and faith.”

Huntsman’s spokesman Tim Miller said the ex-governor has a policy of not signing any pledges. “He has been a clear supporter of traditonal marriage and will let his record speak for itself.”

Drew Ivers, Iowa campaign chairman for Paul’s campaign, said the congressman has concerns about the pledge because it calls for a federal marriage amendment to the U.S. Constitution. “He is very strong pro-traditional marriage, but he doesn’t want the government to dictate and define traditional marriage. That should be between a man and a woman and the church if they choose to have a church wedding.”

The candidates are being asked to respond to the pledge requests by Aug. 1. Vander Plaats said he expects the responses to be shared with the public around the time of the Iowa State Fair, which begins Aug. 11 and prior to the Ames Straw Poll on Aug. 13.

Vander Plaats said the decision to seek pledges came in response to some recent events. This included the New York Legislature’s approval of same-sex marriage, as well as sex scandals involving former U.S. Rep. Anthony Weiner of New York and former California Gov. Arnold Schwarzenegger

Former state Sen. Jeff Angelo of Ames, who recently established a group known as Iowa Republicans for Freedom, which supports same-sex marriage, issued a statement criticizing the marriage pledge.

“Iowans are having a very important dialogue about ensuring that all residents are treated fairly by their government–a long-standing and central principle of our state. This pledge is an attempt to shut down dialogue between voters and the people vying to represent them,” Angelo said.